1. Field of the Invention
The present invention generally relates to measuring instruments. More specifically, the present invention is drawn to a hand-held device which utilizes the triangulation method for determining distance.
2. Description of Related Art
There are many devices available in the art which are utilized to determine the height of an object when direct measurement is difficult or impossible. These prior art devices employ the triangulation method for making the aforestated height determination. Examples of such prior art devices are shown in U.S. Pat. Nos. 1,253,877 (Payne), 1,274,315 (Olin) and East German Patent number 143,635. It is noted that the instant patents are only concerned with ascertaining the height of an object.
U.S. Pat. Nos. 1,398,853 (Ginzbourg) and 3,639,997 (Koeber) disclose devices for determining the distance of objects in order that a camera may be properly focused. There is no teaching in the immediately above patents for determining the height of an object.
U.S. Pat. Nos. 4,368,581 (Tullos) and 6,079,111 (Williams et al.) disclose range finder apparatuses which are attached to archery bows. The apparatuses are designed to be used only for archery functions.
U.S. Pat. No. 1,901,880 (Shuster) discloses a triangulation device which can be used to determine both height and distance. The device however, is relatively large and must be supported on a tripod.
None of the above inventions and patents, taken either singly or in combination, is seen to disclose a hand-held range and/or height determining device as will be subsequently described and claimed in the instant invention.
In the science of trigonometry, it is well known that all properties (length of the three sides and inclination of the two acute angles) of a right triangle may be determined if the length of one side of the triangle and the inclination of one of the acute angles is known. By employing established trigonometric ratios such as the tangent, sine, cosine, etc., the device of the present invention is capable of quickly and easily determining the range or the height of a distant object.
The device of the present invention comprises a palm-sized housing having merely four main components; (1) a retractable tape measure; (2) a sighting slot; (3) a pendulum and (4) a calibrated graph. A reel is disposed on the rear wall of the housing to provide means for retracting the tape measure. The calibrated graph is imprinted on the face of a thin sheet, which sheet is attached to the front wall of the housing. A transparent cover is disposed to protect the face of the sheet. The pendulum is supported from a pivot point and is deployed between the cover and the sheet to swing freely over the face of the sheet (and graph) when the device is in use. An offset portion on the sheet functions to prevent the pendulum from swinging freely when the device is not in use. The sighting slot is positioned at the top of the housing.
Accordingly, it is a principal object of the invention to provide a measuring device for determining, by triangulation, the range of a distant object.
It is another object of the invention to provide a measuring device for determining, by triangulation, the height of a distant object.
It is a further object of the invention to provide a measuring device which is compact and durable.
Still a further object of the invention is to provide a measuring device which is easy to use.
It is an object of the invention to provide improved elements and arrangements thereof in a device for the purposes described which are inexpensive, dependable and fully effective in accomplishing their intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.